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Wear Measurement (cont.) Cleanliness of specimens was an on-going source of error –isolated early occasions where heavy oil and grit in threaded and center point vee were found gave up to 0.15 gm error in weight –improved, but still easily up to 0.01 gm error when missed Due to cleanliness issues, a second method of wear assessment based on visual ratings was developed and used in addition to wgts

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Visual Appearance of Coated Rods All tested rods visually rated from 1-10 Initial L12 DOE specimens showed wide range of wear scar appeances. Picked least damaged as a 1 and worst damaged as a 10. Selected others as 2, 3, 6, 7, and 8 and adopted these as photostandards for rating rods. All rods laid out and compared side by side with the original rods of the standards (not to photos which follow)